In the semiconductor field, each set of wafers fabricated is typically performance tested, before they are diced into individual integrated circuits. FIGS. 1-4 show equipment that is used in this testing. Although these figures show an embodiment of the invention they also show some features that are shared with prior art systems. These features are referenced in this section to help explain the context of the invention.
To perform wafer testing a piece of equipment known as a probe station 10 has a head plate 12 that defines an original head plate aperture 14 FIG. 3. The aperture supports a circular device known as a probe card dish 16, which in turn supports the probe card 17. A separate piece of equipment, known as a tester 18 having docking units 20, is lowered into mating position with respect to the probe station, the probe card dish and the probe card. Sometimes probe station 10 includes an obstacle, such as a wafer loader cover 19, that is too close to the original head plate aperture 14 to permit the docking of a particular tester 18.
Generally, a number of guides and associated docking equipment pieces are needed to successfully dock a tester to a probe station, a probe card dish and the wafer that the probe card dish supports. Probe stations are generally sold to semiconductor manufacturing facilities with this docking equipment already installed. Accordingly, when a new tester is purchased it is typically necessary to purchase a new probe station fitted with docking equipment to facilitate docking with the new tester. Unfortunately, the docking equipment, which is typically installed by the probe station vendor or a secondary source, generally permits docking to a single make of tester. The installation of docking equipment to permit the use of a different tester with the probe station is referred to in the industry as xe2x80x9chardware swap-outxe2x80x9d and results in extensive use of technician time and equipment down time.
It is known to machine a single prober to accept a single tooling plate that permits docking to a desired tester. There appears, however, not to have been an effort in the prior art to produce a set of standardized tooling plates that could each be used on any one of a set of differing probe stations. As a result, only very limited flexibility was gained by this method.
Another issue facing semiconductor manufacturers is the lack of uniformity of head plate apertures, between the various commercial lines of probe stations. The unfortunate result is that there is currently no known technique for mating a probe station having a first head plate aperture size with a tester designed to mate with a prober having a second head plate aperture size.
In a first separate aspect the present invention is a method of retrofitting a probe station having an original head plate, so that the probe station may be easily configured to mate with a probe card dish and any tester out of a set of testers. First, the original head plate is removed from the probe station and a replacement head plate, including head plate-tooling plate attachment region alignment items, is attached to the probe station. In addition a set of tooling plates, each having fastening and alignment items adapted to easily mate to the head plate-tooling plate attachment region fastening and alignment items and defining an aperture designed to engage a probe card dish and including docking equipment adapted to facilitate docking to a tester out of the set of testers, the set of tooling plates including, for each particular tester out of the set of testers, a tooling plate adapted to facilitate attachment to the particular tester.
In a second separate aspect, the present invention is a method of retrofitting a probe station having a head plate that defines an original head plate major aperture. After the retrofit, the probe station is adapted to mate with a predetermined probe card dish and a predetermined tester that the probe station could not mate with prior to being retrofitted. First the original head plate is removed from the probe station and a replacement headplate is attached in its place. The replacement head plate has a head plate-tooling plate attachment region, including head plate-tooling plate attachment region alignment items and has a larger major aperture than the original head plate. A tooling plate having tooling plate fastening and alignment items adapted to mate to the head plate-tooling plate attachment region fastening and alignment items is mated and fastened to the replacement head plate. The tooling plate major aperture is designed to engage the predetermined probe card dish and is positioned relative to the tooling plate fastening and alignment items such that once the tooling plate is installed the tooling plate major aperture is not coincident to the original head plate major aperture.
In a third separate aspect, the present invention is a method of retrofitting a probe station having a horizontal extent and including an original head plate, so that the probe station can mate to a probe card dish and to a tester that includes docking equipment that extends horizontally beyond the horizontal extent of the probe station. The method begins with removing the original head plate from the probe station and replacing it with a replacement head plate having a head plate-tooling plate attachment region. This region includes head plate-tooling plate attachment region alignment items. The replacement head plate also has at least one docking equipment attachment plate attachment region having docking equipment attachment plate alignment item. At least one docking equipment attachment plate adapted to mate to one of the attachment regions and including a piece of docking equipment, is attached to a corresponding attachment region. At least one of these docking equipment attachment plates protrudes horizontally outwardly from the replacement head plate and supports one of the pieces of docking equipment outwardly of the replacement headplate. Also, a tooling plate defining an aperture adapted to support the probe card dish is attached to the head plate-tooling plate attachment region.
The foregoing and other objectives, features and advantages of the invention will be more readily understood upon consideration of the following detailed description of the preferred embodiment(s), taken in conjunction with the accompanying drawings. dr
FIG. 1 is a side view of a probe station-tester mating pair wherein the probe station has been retrofitted according to the method of the present invention.
FIG. 2 is a top view of the probe station of FIG. 1.
FIG. 3 is an exploded perspective view of a portion of the probe station of FIG. 1, showing some of the details of the retrofitting of the present invention.
FIG. 4 is an a perspective view of a tooling plate and docking equipment attached to the tooling plate.
FIG. 5 is a perspective view of another embodiment of a tooling plate.